Optical emission represents the bulk property of plasma, which in turn can be correlated to the
chamber surface condition and can be exploited for monitoring and characterizing chamber
condition. This presentation demonstrates the approach of utilizing plasma optical emission spectra
(OES) for the application on Applied Materials' TetraTM etcher chamber condition monitor. Time-resolved
plasma optical emission spectra are collected with a spectrometry unit built in to the
TetraTM photomask etch module. Studies on OES analysis show that information related to chamber
surface condition can be correlated to the changes in emission spectrum of plasma. The effectiveness
of this methodology can be verified by Cr etch rates. Results can lead to procedure development for
chamber monitoring, chamber recovery and chamber seasoning applications.